Jim Crow was not a person. Jim Crow refers to laws and attitudes that segregated white Americans and black Americans. Although the Reconstruction Amendments provided for freedom of slaves and voting rights, it had little change on enforcing equality.
This video, produced by California Newsreels, summarizes Jim Crow laws.
The Supreme Court case of Plessy v. Ferguson in 1896 established the ruling of "separate but equal" and was the foundation of effectively legalizing segregation.